Holiday front end

[tkakar0451]

Description

This PR adds an administrator workflow for creating and managing holiday exceptions used by OED's time-varying conversion system, but it does not apply holiday exceptions while calculating conversions. That future server side RRule work is tracked separately in issue #1681

The workflow consists of three new connected holiday administration pages, with an additional integration into the existing Week Patterns page:

• Holidays: Allows an administrator to select a location and add the base holidays that should be available in OED.
• Holiday Rates: Allows an administrator to pair one saved base holiday with one day pattern. The page supports creating, viewing, editing, and deleting Holiday Rates, filtering base holidays by location, validating required fields, displaying saved rates as cards, and saving changes through the OED API.
• Holiday Rate Groups: Allows an administrator to combine multiple Holiday Rates into reusable groups for the time-varying conversion workflow.
• Week patterns: Adds an optional Holiday Rate Group selection to Week Patterns.

This PR also includes the frontend routes, navigation entries, Redux API integration, translations, help text, notifications, database tables, models, queries, and server routes needed to support the three-page holiday workflow.

Contributors

• @RoseArias: Holidays page and location-based holiday selection workflow.
• @tkakar0451: Holiday Rates page, including create, edit, delete, validation, location filtering, Redux API integration, translations, notifications, and help content.
• @JSmevog1: Holiday Rate Groups page and its connection to the time-varying conversion workflow.

Testing

• Manually tested the complete three-page holiday workflow.
• Confirmed that the Holidays, Holiday Rates, and Holiday Rate Groups pages load and operate correctly.
• Confirmed that records created on one page are available to the next page in the workflow.
• Confirmed create, edit, and permitted delete operations.
• Confirmed that the delete interlock prevents a Holiday Rate from being deleted while it is referenced by a Holiday Rate Group.
• No new holiday-specific automated tests were added.

No existing GitHub issue was identified specifically for the three-page holiday administration workflow.

Type of change

• Note merging this changes the database configuration.
• This change requires a documentation update

Checklist

• I have followed the OED pull request ideas
• I have removed text in ( ) from the issue request
• You acknowledge that every person contributing to this work has signed the OED Contributing License Agreement and each author is listed in the Description section.

Limitations

• No automated tests were added specifically for the new holiday functionality. The complete three-page workflow was tested manually, but automated regression coverage should be added in future work.
• The Holiday Rates page does not yet check for duplicate names or duplicate base-holiday/day-pattern combinations before saving. The database enforces these restrictions, but the user may receive a general failure notification instead of field-level feedback.
• A Holiday Rate cannot be deleted while it is referenced by a Holiday Rate Group. The database interlock correctly protects the relationship, but the page does not check for that relationship before sending the delete request, so the user may receive a general deletion failure message rather than a specific explanation.
• The Holiday Rates page still contains some page-local confirmation, selection, unsaved-change, and styling logic that could be migrated to OED's shared components in future cleanup.
• Holidays page:
• Importing is immediate and imports all holidays returned for the selected location and year. There is no preview or confirmation step and no way to select individual holidays before saving
• Previously imported location and year combinations are not displayed as separate manageable items. Administrators must reselect the location and year to view them, and those selections are not retained after leaving the page.
• The date-holiday api does not have a good way to indicate historical holidays and their start and end dates. Admins should review historical schedules before using imported holidays.
• Location is stored as one combination code, A future redesign should consider providing holiday location/region cards instead of the holidays themselves.
• The page does not currently provide a safe way to delete an accidentally imported holiday/region. Dependency checks would be needed before deletion.
• Holiday and location names are currently requested from the date-holidays api in English regardless of OED’s language.
  Holiday Rate Groups page
  -The Holiday Rate Groups page does not yet check for duplicate names before saving, a user friendly error message shows up, but the create or save button should not be clickable if the name is a duplicate.
  -In the Holiday Rate Groups page, you can not select a holiday rate without selecting a location first. Users should be able to choose holiday rates without location selected and selecting a location just filters holiday rates.
  -In the holiday Rate Groups page, holiday rates is a required input, therefore should be highlighted red when empty. It is not highlighted as of now.
  -A Holiday Rate Group cannot be deleted while it is referenced by a weekly pattern. The database interlock correctly protects the relationship, but the page does not check for that relationship before sending the delete request, so the user may receive a general deletion failure message rather than a specific explanation.
  -A schema issue related to weeks prevents holiday rate groups from saving when creating weekly patterns.